Yep fasting for 14 days would certainly increase the effectiveness of the fast to decrease arterial plaque. Fasting worked well for me to do just that.
Electrolyte balance: If your diet was excellent before the fast I would tend to conclude that you were okay and consequently your electrolyte balance should be fine. The weakness you describe is a common "complaint" that sort of weakness is not something that would stop me fasting and in itself isn't a sign of electrolyte imbalance.
There are a number of posts here concerning electrolyte balance and symptoms. A quick peruse of those revealed nothing of concern in your case. Feel free to follow up that line of enquiry. If you moved to juice that would help at the end of the fast so you'll be fine no matter what.
Happy fasting: I loved the body "re-roganisation" happening under my skin to solve this issue. T2